replacing NAN with missing value

[mathias1979]

I'm working with fortran 77 on pgi compilters. I need to go through a real array and replace occurrances of NAN with -9999. I was just trying a simple if statement such as:

if (test(i,j).eq.NAN) test(i,j)=-9999

This just seems to ignore occurances of NAN. And if I try to do something like test(i,j).eq.'NAN') I get a type mismatch error. How can I get around this?

 

[xwb]

Testing against NAN doesn't work because, by normal Fortran rules, (identifiers beginning with letters I-N are integers) NAN is just an integer variable whose initial value is probably zero or some random number.

Testing for 'NAN' as a string won't work because you are comparing a number with a string.

This may or may not work on your compiler

   if (isnan(test(i,j)) test(i,j) = -999